Histology: Mechanisms Of Tooth Development

Front 1

Only the _______ ( _________________) pharyngeal arch forms teeth.

Back 1

first; mandibular

Front 2

ectomesenchyme of the ________ _________forms dentin (odontoblasts) and pulp.

Back 2

dental papilla

Front 3

ectomesenchyme of the ________ ______ forms the PDL, alveolar bone, and cementum.

Back 3

dental sac

Front 4

What are the 4 fundamental principles of tooth development?

Back 4

1. the tooth is of dual origin (epithelium forms enamel & ectomesenchyme forms dentin and pulp)
2. only the first pharyngeal arch (mandibular arch) is involved in tooth formation
3. migration of neural crest cells into the first arch is required
4. reciprocal induction between oral epithelium and ectomesenchyme is required

Front 5

Prior to day 12, ____________ initiates odontogenesis. After day 12, ______________ directs the development of the tooth.

Back 5

epithelium; ectomesenchyme

Front 6

___________________ derived from neural crest cells forms CT while ______________ and _________ form muscles.

Back 6

ectomesenchyme; somatomeres and somites form muscles

Front 7

What are the two divisions of paraxial mesoderm?

Back 7

1. somatomeres -craniofacial muscles
2. somites -tongue and body muscles

Front 8

______________ give rise to craniofacial muscles.

Back 8

somatomeres

Front 9

_____________ give rise to tongue and body muscles.

Back 9

somites

Front 10

failure of NCC to migrate to proper position; results in severe dysformity

Back 10

mandibulofacial dysostosis

Front 11

What are the two predominant molecular signaling mechanisms observed during tooth development?

Back 11

1. homeobox genes
2. growth factors

Front 12

genes that guide emergence of general shape and form in embryos; encode transcription factors; contain highly conserved sequences of 180 bp

Back 12

homeobox genes

Front 13

tooth development involves over ___ genes

Back 13

70

Front 14

responsible for specialization of segments and segment identity in drosophila

Back 14

homeotic genes

Front 15

homeobox genes associated with the NCC migration from rhombomeres 4,6,8

Back 15

Hox family of craniofacial homeobox genes

Front 16

Homeobox gene assocaited with muscle development in drosophila

Back 16

Msx

Front 17

Homeobox genes associated with limb development in drosophila

Back 17

Dlx

Front 18

Homeobox gene associated with retina development in drosophila

Back 18

Barx

Front 19

What are homeobox genes?

Back 19

genes that guide emergence of general shape and form in embryos

Front 20

What directs the formation of the dental lamina?

Back 20

Msx1, Msx2 and Dlx2

Front 21

The term for the conserved 60 AA region of the transcription factor for homeobox genes

Back 21

homeodomain

Front 22

Tissue that controls tooth development during initiation stage

Back 22

epithelium

Front 23

Is first arch epithelium necessary for the expression of Lhx-6 and Lhx-7 in the ectomesenchyme?

Back 23

Yes, first arch epithelium is required for the initiation of tooth formation

Front 24

Lhx-6 and Lhx-7 are __________ _________________

Back 24

transcription factors

Front 25

The family of genes associated with neural crest cells that migrate into pharyngeal arches 2 through 4

Back 25

Hox

Front 26

Tissue that controls tooth development during morphogenesis stage

Back 26

Ectomesenchyme

Front 27

Homeobox genes associated with the development of the dental lamina

Back 27

Msx-1, Msx-2, and Dlx-2

Front 28

Secreted proteins that bind to receptors on cell surface

Back 28

growth factors

Front 29

The homeobox genes expressed in ectomesenchyme of developing incisor

Back 29

Msx-1 and Msx-2

Front 30

The homeobox genes expressed in ectomesenchyme of developing canine

Back 30

Msx-1, Msx-2, Dlx-2 (Mike, Martyn and Don)

Front 31

The homeobox genes expressed in developing molar

Back 31

Barx-1 and Dlx-2

Front 32

The control of expression of which genes indicates that the first arch epithelium is needed for the initiation of tooth formation?

Back 32

Lhx-6 & Lhx-7 (Luke & Larry)

Front 33

Colocailzaiton of these two genes controls the number and position of teeth

Back 33

Fgf-8 and Pax-9

Front 34

The tissue in which Pax-9 in located

Back 34

ectomesenchyme

Front 35

The tissue in which Fgf-8 is located

Back 35

epithelium

Front 36

Gene that may cause the invagination of the oral epithelium to form tooth buds

Back 36

Shh

Front 37

Expression of ______ results in the formation of tooth buds

Back 37

Shh

Front 38

The protein that indicates that the control of tooth development is transferred from the epithelium to the connective tissue

Back 38

BMP-4

Front 39

The growth factor that causes growth of the lateral aspect of the enamel organ forming the cap-shape

Back 39

TGF-B

Front 40

Structure associated with the symmetry of the cuspal tips

Back 40

enamel knot

Front 41

Expression of which gene is necessary for the development of the molars?

Back 41

Pax-9

Front 42

What is observed in Pax-9 knock-out mice?

Back 42

arrested development of molar formation